We first outline the procedure of averaging the incompressible Navier-Stokes equations when the flow is turbulent for various type of filters. We introduce the turbulence model called Bardina’s model, for which we are able to prove existence and uniqueness of a distributional solution. In order to reconstruct some of the flow frequencies that are underestimated by Bardina’s model, we next introduce the approximate deconvolution model (ADM). We prove existence and uniqueness of a “regular weak solution”...

This paper is devoted to the study of a turbulent circulation model. Equations are derived from the “Navier-Stokes turbulent kinetic energy” system. Some simplifications are performed but attention is focused on non linearities linked to turbulent eddy viscosity ${\nu}_{t}$. The mixing length $\ell $ acts as a parameter which controls the turbulent part in ${\nu}_{t}$. The main theoretical results that we have obtained concern the uniqueness of the solution for bounded eddy viscosities and small values of $\ell $ and its asymptotic...

This paper is devoted to the study of a turbulent
circulation model. Equations are derived from the “Navier-Stokes turbulent
kinetic energy” system. Some simplifications are performed but attention
is focused on non linearities linked to turbulent eddy viscosity ${\nu}_{t}$. The mixing length $\ell $ acts as a parameter which controls the
turbulent part in ${\nu}_{t}$. The main theoretical results that we have
obtained concern the uniqueness of the solution for bounded eddy viscosities
and small values of $\ell $ and its asymptotic...

In this paper, we establish the large-data and long-time existence of a suitable weak solution to an initial and boundary value problem driven by a system of partial differential equations consisting of the Navier-Stokes equations with the viscosity $\nu $ polynomially increasing with a scalar quantity $k$ that evolves according to an evolutionary convection diffusion equation with the right hand side $\nu \left(k\right)|\U0001d5a3\left(\overrightarrow{v}\right){|}^{2}$ that is merely ${L}^{1}$-integrable over space and time. We also formulate a conjecture concerning regularity...

The hydrostatic approximation of the incompressible 3D stationary
Navier-Stokes equations is widely used in oceanography and other
applied sciences. It appears through a limit process due to
the anisotropy of the domain in use, an ocean, and it is usually studied as
such.
We consider in this paper an equivalent formulation to this
hydrostatic approximation that includes Coriolis force and an additional
pressure term that comes from taking into account the
pressure in the state equation for...

The hydrostatic approximation of the incompressible 3D stationary
Navier-Stokes equations is widely used in oceanography and other
applied sciences. It appears through a limit process due to
the anisotropy of the domain in use, an ocean, and it is usually studied as
such.
We consider in this paper an equivalent formulation to this
hydrostatic approximation that includes Coriolis force and an additional
pressure term that comes from taking into account the
pressure in the state equation for...

We introduce in this paper some elements for the mathematical and numerical analysis of algebraic turbulence models for
oceanic surface mixing layers. In these models the turbulent diffusions are parameterized by means of the gradient Richardson number, that measures the balance between stabilizing buoyancy forces and destabilizing shearing forces. We analyze the existence and linear exponential asymptotic stability of continuous and discrete equilibria states. We also analyze the well-posedness...

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